sin(-4π／3)cos(-23π/6)tan(25π/4)=?

利用和差角公式化简 (2)sin(π/3+α)+sin(π/3-α)(2)sin(π/3+α)+sin(π/3-α)(3)cos(π/4+α)-cos(π/4-α)(4)cos(60°+α)+cos(60°-α)(5)sin(α-β)cosβ+cos(α-β)sinβ(6)cos(α+β)cosβ+sin(α+β)sinβ 由cos(a+b)=cos a cos b-sin a sin b cos(a-b)=cos a cos b+sin a sin b解题设a为锐角,证：1、2分之根3乘cos a + 2分之1乘sin a=cos(6分之π-a)2、cos a-sin a=根号2cos(4分之π+a) 怎样化简函数 cosπ/4cosπ/3-sinπ/4sinπ/3cosπ/4cosπ/3-sinπ/4sinπ/3 cos(-23π/4)+sin(37π/6) 已知sin[a-b]cos a-cos[b-a]sin a=3/5,b是第三象限角,求sin[b+5π/4]的值第一题1/2cos x-√3/2sin x第二题√3sin x+cos x第三题√2[sin x-cos x]第四题√2cos x-√6sin x 化简:sin(π/4-α)cos(π/3-α)-cos(π/6+α)sin(π/4+α)= [Sin(6π+a)Cos(7π-a)]/[Sin(3π+a)+Sin(-π+a) sin(-4π／3)cos(-23π/6)tan(25π/4)=? 化简:sin(-4π/3)cos(-23π/6)tan25π/4 已知tan（α+π/4）=3,计算2sinαcosα+6cos方α-3/5cos方α-6sinαcosα-5sin方α 1.化简根号2cos x - 根号6sin x2.已知sin(α-β)cosα-cos(β-α)sinα=3/5,β是第三象限角,求sin(β+5π/4)的值.3.化简sin(α-β)sin(β-λ)-cos(α-β)cos(λ-β) 设角a=-35π/6,则2sin(π+α)cos(π-α)-cos(π+α)/ 1+sin^2α+sin(π-α)-cos^2(π+α)sina=sin(-35π/6)=sin(-6π+π/6)=1/2 cosα=根号3/22sin(π＋α)cos(π-α)-cos(π+α)/ [1+sin^2α+sin(π-α)-cos^2(π+α)]=2（-sinα)(-cosα）+cosα/[1+sin² 已知0＜α＜π/2,且3sinα=4cosα求(sin^2α+2sinαcosα)/(3cos^2α-1)求cos^2α+sinαcosα 已知sinα+cosα=4/5且3π/22,若sinα+sinβ+sinγ=0,cosα+cosβ+cosγ=0,则cos(α-β)的值 ：（1）sin（2π-α）cos（π+α）cos（π/2+α）cos（13π/2-α）/cos（π-α）sin（5π-α）sin（-π-α）sin（9π/2+α）（2）sin（25π/6）+cos（25π/3）+tan（-27π/4） sin（-19π/6）=?已知[3Sin(π+a)+Cos(π-a)]/4Sin(-a)-Sin(5π/2+a)=2，求tan a 已知6sin²α+sinαcosα-2cos²α=0,α∈（π/2,π）,求值1).(sinα-3cosα）/（sinα-cosα）；2）.sinαcosα-sin²α;3).sin²α-3cosαsinα-2 化简sin(α-5π)/cos(3π-α)×cos(π/2-α)/sin(α-3π)×cos(8π-α)/sin(-α-4π)